Gun sight



, ET AL ZATQ 7 W. F. BERNART, JR.

Aug. 23, 1949.

GUN SIGHT Filed May 15, 1945 6 Sheets-Sheet l mmm. .w

SWW/wm Willum F EJEPl-Lurhd: Franc-ia T T- Ruuun HCH ROG? Aug. 23, 1949. w. F, BRNART, JR., ET AL 2,479,717

GUN SIGHT 6 Sheevts-Sheet 2 Filed May l5, 1945 aum/wmp Aug, 23; E949. w. F. BERNART, JR., ETAL j 27479973? GUN SIGHT Filed 'May 15, '1945 e sheets-sheet s Inman/(Uw Willinm F. Barum-righ:

w. F. BERNART, JR., ET AL GUN SIGHT 6 Sheets-Sheet 4 Filed May 15, 1945 Aug, 23, 1949.

Flled May 15, 1945 Aug. `23, 1949. w. F. BERNART, JR., ET A1. 2,479,717

GUN SIGHT l l l Filed May 15, 1945 t e sheets-sheet e Willium 'E Elernurc,1ln Francia 1J- Rnuun Patented Aug. 23, 1949 tttitti RM UNITED STATES PATENT OFFICE GUN SIGHT Application May 15, 1945, Serial No. 593,930

21 Claims.

,y This invention relates to the computing sight for lire-arms invented by Herbert K. Weiss and covered by application for patent Serial No. 560,831, filed in the Unit-ed State Patent Oice on October 28, 1944, for Gun sight, and the device herein presented will also be termed a Weiss sight. The object of the instant invention is to improve, simplify and cheapen certain of the parts, mechanisms and details of the said computing sight, as will appear or be pointed out in the embodiment shown in the accompanying drawings, wherein:

Figure 1 is an isometric view of the improved Weiss sight of this invention,

Figure 2 is a plan view of the system,

Figure 3 is a Side elevation taken from the right-hand side of Fig. 2,

Figure 4 is a sectional elevation t-aken on the line 4--4 of Fig. 2,

Figure 5 is likewise a sectional elevation but taken on the line 5-5 of Fig. 2,

Figure 6 is a partial rear sectional elevation taken on the line 6-6 of Fig. 2,

Figurev 7 is a sectional elevation taken through the gear box on the line 1-1 of Fig. 2 (the arrow Il] in Fig. 7 is, however, turned 90 to its position shown in Fig. 2),

Figure 8 is a side elevation, half in section, through the s-aid gear box 20 taken on the line 8-8 of Fig. 7,

Figure 9 is a diagrammatic right elevational showing of the gun, azimuth trackers telescope and associated parts, the gun being in an elevated position,

Figure 10 is an enlarged detail of the superelevation mechanism corresponding to the position of the gun and telescope shown in Fig. 9,

Fig. 9-a is a diagrammatic showing similar to Fig. `9, but with the gun in a horizontal position.

Figure l0-a is an enlarged detail similar to Fig. 10 but corresponding to the position of the gun and telescope of Fig. 9-a,

Figure 11 is a detail of the direction hand setting connection between the hand wheel 69 and the automatic orienting connection between the ,azimuth drive of the 40 mm. or like guns.

Figure 12 is a formal detail of the differential connection between the hand set speed indicator and the shaft 41.

Figure 13 is a schematic view similar to Fig. 1 modified in some details but showing the gun formally, all of the essential parts being as iirst described; the case 20 being removed, and the gearing being partly exploded to enable a showing 2 of the complete system illustrated in Figures 7 and 8.

The present sight is especially intended for guns such as the Armys 40 mm. anti-aircraft gun. Such guns are sighted by two operators, a trainer and a pointer, located at sights and 90, respectively. The two sights are carried by the gun cradle and are interconnected to maintain their lines of sight parallel. The trainer, looking through his telescope 50, operates his hand wheel 59 to traverse or train the gun and thereby keep the vertical cross hair of his telescope on the target. Likewise, the pointer, looking through his telescope 90, operates his hand wheel 99, Figure 2, to change the elevation of the gun at the rate necessary to keep the horizontal cross hair of his telescope upon the target.

Prior to the development of the Weiss sight, it was the duty of the trainer and pointer or azimuth and elevation trackers, to sight the plane target within a predetermined portion of a circular grille sight, depending upon an approximation of the speed and direction of the path of travel of the plane, in order to compensate for the necessary lead. In the operation of this sight, a third man, who will be herein referred to as the sight setter, is required to set course and speed (of the target) on the sight. Hence the two trackers are concerned only with one job, that of maintaining the .plane target centered in the respective azimuth and elevation sights. This pre-setting (by the sight setter) for direction of flight and speed introduces a lateral lead in the azimuth tracking telescope, which is communicated to the elevation tracking telescope, in order that the adjustment for lead may not disturb the elevation tracking.

The sight setter pre-sets the Weiss sight for direction o1 flight and speed by aligning a small arrow I0, Fig. l, with the axis of the airplane and pointing it in the direction of its flight Iand by turning a hand wheel 30, Fig. 1, until the approximate airplane speed appears in indicator window 22 of the case or box 20 to be described. The setting of arrow l0 in accordance with course and the adjusting of hand wheel 30 in accordance with speed, introduces lead into the azimuth tracking telescope 50 in the manner now to be explained. Azimuth telescope 50 is clamped in a xture 5I which is pivotally mounted on a horizontal axis in the upper forked end of a short post 52 (shown vertical in Fig. l) which uprises from a bearing member or box 53. A slight adjustment about the horizontal pivot is thus provided; a clamping arm 5 I -a is iixed to the horizontal pivot amari? and is mounted to turn with fixture 5I and may be secured when adjusted to the post 52 by the bolt and slot arrangement shown in Figs. 1 and 3. An adjustment of the telescope about the substantially vertical axis of post 52 is provided by a spindle 53 engaged axially in the lower split end of the post and through a hub 53s of the said box 53. The post is secured when adjusted to the hub 53s by the split bearing and clamp bolt 530 on the post shown in Figs. 1 and 3. These adjustments make possible the accurate setting of the telescope when the gun and sights are originally set with respect to a fixed target, a procedure known as bore sighting which is Well understood.

Bearing box member 53 has front and rear legs which are parallel to each other and provided with bearings for a tubular rod 54, within which slidably lits a rod 54', the two rods 54--54 thus constituting a telescoping linkage. The front end (Fig. 1) of the rod 54 is universally pivoted to the under side of a lead nut 55 movably adjustable along a lead screw 56. The said two legs of box 53 are joined by a lower bridge piece, Fig. 1, having a centrally located transverse, horizontal bearing 53h in which a stud rod 51 is set, projecting to the left. The spindle 53 (see Fig. 3) is passed midway through the said box 53, being pinned near its top in the hub 53s of the box and journaled at the bottom in the top portion of bearing 53h. This pin or spindle 53 passes through a hole provided in telescopic rod 54 (see Fig. 3), thus blocking axial movement of rod 54 and fork 45j in the box 53, but it should be understood that the pin 53' is free to rotate in the arms of the fork 45j, as will appear. The fork may rotate on the longitudinal axis of its shaft 45. The rod 54 is fitted between the arms 45j so that upon raising or lowering of the lead screw the shaft 45 will be rocked.

The adjustment of nut 55 along lead screw 56 (according to the speed of the plane target, as will be more fully described) causes, by means of telescoping linkage 54-54, azimuth turning of box 53, post 52 and azimuth telescope 50, about the axis determined by the aforesaid pin or spindle 53. In this manner lateral deflection or lead is given to azimuth telescope 50, by turning relatively to the gun in a sense or direction opposite to the direction of movement of the target. For example, in Fig. 1, the target moves from right to left, the arrow I being pointed to the left. Hence the nut 55 is adjusted to the right so as to lturn telescope 5U in that direction (clockwise in Fig. 1). The reason for turning the azimuth telescope in a direction opposite to target flight is to cause, when the azimuth telescope is sighted on the target, a movement of the gun in the direction of travel of the target and in advance of the present target position, the extent of advance being the lead to compensate for time of flight of the projectile.

In order to maintain the lines of sight of telescope 50 and 90 parallel, it is necessary to laterally turn the elevation telescope 90 with the azimuth telescope 50. For this purpose the stud rod 51 is universally pivoted at its swinging left end, as at 51a to the rear end of a long link 51', Fig. 1, the front end of which is connected, through universal pivot connections shown in Fig. 1, to an arm 58B. depending from the right end of a long rock shaft 58, which extends from the right-hand or azimuth side of the gun to the left-hand or elevation side of the gun through the cross tube 2 (Figs. 2 and 5). At its left end the shaft 58 is provided with a similar depending arm 58L which is connected, through similar universal connections, to the front end of a long link 91', the rear end of which, Fig. 1, is universally pivoted at 91a, to the left end of a short stud 91, the right end of which is set in a bearing 93h of a box 93 similar to the box 53 except that it is not provided with fore and aft bearings, and there is no telescoping linkage similar to that at 54-54'. Elevation telescope 90' is mounted at 9| on a post 92 of box-like member 93 in a manner similar to the mounting arrangement of the azimuth telescope 5U, corresponding parts bearing reference characters having the same numerals in the first-order place. The elevation box 93 has a pin or spindle 93' Fig. 1 similar to the pin or spindle 53 of azimuth member 53, about which the elevation telescope turns in azimuth. That is, the azimuth tracking telescope 59 turns in azimuth about the pin or spindle 53' of box while the elevation tracking telescope 90 turns likewise in azimuth about the pin or spindle 93 of the box 93, both telescopes turning in synchronism.

Theaforementioned direction of iiight arrow I0 is mounted in a horizontal position on a vertically disposed stud shaft II, Figs. 7 and 13, at the top of box or case 20 which is made of separable parts including a framing for gearing, to be described. Secured on stud shaft II is a gear I2 which meshes with a pinion I3 Secured at the upper end of a countershaft I4, Fig. 8, which is vertically disposed in control box 20. At the lower end of vertical shaft I4 is a pinion I5 which meshes with a gear I6 which is fixed to a horizontally swingable bracket member I1, Fig. '7, which supports the previously described lead screw 56. An adjustment of arrow I 0 to a position parallel to the line of flight of a plane will rotate the gear I6 and the swingable bracket member I1, to move the lead screw angularly around a vertical axis in a horizontal plane to a position also parallel to the line of flight of the plane target, which is the essential of such setting. The gearing between arrow I0 and gear I6 being 1:1, the lead screw will always have position parallel to and oppositely directed with respect to the arrow.

As more fully explained in the aforesaid Weiss patent application, the lead screw is maintained in a horizontal position irrespective of gun elevation. Here shaft I4, Fig. 8, and control box 20 corresponding to the floating frame of the Weiss application are always maintained vertical. To maintain control box 20 vertical irrespective of gun elevation the following means is provided: Control box 20 is rigidly secured by an elbow bracket ZI, Fig. 1, to a horizontal shaft 23. The shaft 23 is journaled at its ends in bearings provided in respective left and right strap link members 43 and 43'. A full view of strap member 43 (in which the left end of shaft 23 is journaled, (see Fig. 6) appears in Fig. 5 where it willbe seen to be pivotally secured at its forward right end to a frame member 3 at 43a. The strap member 43 (in which the right end of shaft 23 is journaled, (see Fig. 6) is similar to the strap member 43, the right strap member 43 being pivotally mounted to a frame member 3'. Left frame member 3 and right frame member 3' are fixedly secured at one end, by means of the bolt arrangement shown in Figs. 2 and 5, to horizontal tubular supporting cross member 2 which is secured to the gun cradle Il by the bolt fastenings shown in Fig. 2. The two frame members 3 and 3 are reinforced at their rear parts by a horizontal brace tube 3a rigidly connected therebetween.

The purpose of the straps 43 and 43 is to hold shaft 23 parallel to cross member 2 while permitting its vertical adjustment for super-elevation, as will be explained in detail hereinafter. But for the object of maintaining the arrow l0 horizontal and the control box vertical (which is the mechanism now being described) the horizontal shaft 23 could just as well be considered as journaled directly in the frame members 3 and 3. The horizontal tubular support 2, to which the frame arms 3 and 3 are rigidly secured, being itself fixed to cradle l of the gun which is elevatable on the trunnion axis of the gun, the horizontal shaft 23 is likewise elevated with the gun barrel. There is secured to the shaft 23 a lever arm 24, see Figs. 5 and 1, the distal end of which is connected by a long link to a pivot 4a, Figs. 1 and 2, on the nonelevating upper gun carriage 4, Fig. 2. This point is at a distance from the trunnion axis of the gun equal to the radius of the arm 24 and on a radius of said axis parallel to the arm 24 aS well as in a vertical plane with said arm parallel to the bore axis of the gun so that, the shaft 23 being normal to said plane and to the bore axis, the link 25, the arm 24, the gun and framing of the sight, and the upper carriage constitute a parallelogram, the members of which are pivotally connected and one of which-the upper carriage-is fixed, relative to the vertical while two members of the parallelogram extend forwardly to the arm 24. Therefore the arm 24 and consequently the shaft 23, control box 20 and the other parts on this shaft remain in a constant position with respect to the vertical as the forward parts of this parallelogram are raised and lowered, which occurs when the gun is elevated or depressed.

Superelevation is introduced by turning azimuth telescope downwardly at its forward end, so that the gun barrel must be correspondingly raised in order to maintain the target in the sight. Aximuth telescope 50 may be depressed for superelevation by lowering the nut and lead screw 56, relative to the telescope and in the present embodiment the entire control box 26, which contains lead screw 56, is lowered, by lowering shaft 23. The degree of superelevation varies with a number of factors including the angle of gun elevation, being proportional to the cosine of the angle of elevation of the gun. As previously explained, the horizontal shaft 23 is journaled at the rear swinging ends of pivoted straps 43 and 43', rather than directly in the frame members 3 and 3', as seen in Figs. 4, 5 and 6. Extending from the left end of shaft 23 is an eccentric pin 26 (initially at the upper side of the shaft 23) which is received in a slot 6 formed longitudinally in the left frame member 3, while extending from the right end of shaft 23 is an eccentric pin '216' coaxial with pin 26 and engaged in a slot 6 in the right frame member 3' The function of this mounting of the shaft may be observed in Figs. 9-a and 10-a which show the positions of the parts when the gun is horizontal, and in Figs. 9 and 10, which represent the positions of the parts when the gun is in the elevated position.

As explained above, when the gun is horizontal the azimuth telescope 5D must be depressed the maximum degree to set in the maximum superelevation. When the gun is horizontal (as in Figs. 5 and 9-a) the horizontal shaft 23 is in its lowermost position relative to the frame 3-3' as well as in the elevational movement with the gun. As the gun is elevated, the shaft 23 must be also additionally raised relative to the shaft 45 and gun so as to decrease the superelevation. It has been described above, with reference to Fig. 5, that lever 24 is turned clockwise relatively to the gun as the gun is elevated (for the purpose of maintaining the control box vertical and its arrow horizontal); thereby shaft 23 likewise turns in a clockwise sense. The eccentric pins 26 and 26 being initially above the center of shaft 23, when shaft 23 turns clockwise the pins bear on the lower sides of the slots and shaft 23 is elevated on the pins slightly. The straps 43-43 swing correspondingly and keep the shaft 23 parallel to the cross member 2 and trunnions of the gun which is the only function of these straps. The extent of upward turning of the shaft (which causes a proportional decrease in superelevation) depends upon and is proportional to the extent of elevation of the gun, being at a maximum limit of upward movement when the gun is elevated into a vertical position, and lowest When the gun is horizontal.

The vertical spindle 53' (about which turns the telescopic rod 54--54, the box-like member 53 and azimuth telescope 5D in introducing lead, as explained above) is rotatively engaged through the upper and lower arms of the forked end 45f of shaft 45 which is journaled in the frame part 3 and bracket H9 Fig. 2, the axis of this shaft being xed in relation to this frame part. As seen in Fig. 1, the superelevation correctional vertical translative movement when shaft 23, control box 26 and nut 55 are raised or lowered relative to the gun is a turning movement about the said short shaft 45, and the linkage 54-54 communicates this turning to the post 52. This turning on short shaft 45 is made possible by the fact that, in the turning of lower bearing 53h, the rod 51 (journaled in 53h, as already described in connection with the azimuth synchronizing of the elevation telescope 96 with the azimuth telescope 50) may swing on the universal connection getwleen its rod 51 and dependent lever 58 R,

Just as the lead turning of azimuth telescope 50 in azimuth must be communicated (in the manner fully described above) to the elevation telescope 90, so the superelevation turning of azimuth telescope 50 in elevation must likewise be communicated to the elevation telescope 9E). This is a function 0f the said short shaft 45 in addition to supporting the telescope 50. In this manner the superelevation turning or rocking of the box-like member 53 (about the short shaft 45, as already described) is communicated through a depending arm 45a fixed on the shaft 45 to a link 46, and at the same time, the upper and lower fork lingers 45f permit azimuth turning of box-like member 53 about the spindle 53' while the rod 54 may oscillate in a horizontal direction between the fingers. The front end of the link -46 is pivoted to a lever 48B depending from the right end of a horizontal cross shaft 48, rockably mounted in the tubular support 2 of the sight framing (Figs. 2 and 5). At the left end of shaft 48 depends a lever 48L pivoted to the front end of a long link 96, the rear end of which is pivoted to a lever a depending from a stud shaft 95 rockingly mounted on a frame piece 96' (Figure 2). The left end of shaft 95 is provided with a Iblock 95h which is received in the box 93 for horizontal rocking movement and provided with a central hole to receive the pin or spindle 93. The superelevation turning of azimuth bearing members 53-45 is thus communicated by arm 45a, link 46, shaft 48 and link 96, to the elevation bearing members 95-93.

It has been previously described that the sight setter points the arrow I0, and consequently lead screw 56, in the direction and parallel to the course of the target. This may be effected by directly grasping and turning the arrow itself, or by operating the hand wheel 69. This preliminary setting of the arrow and lead screw tends to soon become disturbed by the azimuth traversing of the gun about its vertical axis, as the azimuth tracker follows the target. To maintain the arrow and the lead screw in the preadjusted positions, parallel to the flight of the plane, during the azimuthal rotation of the gun, a connection is provided from the azimuth trackers crank 59, Fig. -1, to the lead screw mounting or bracket member Il and arrow I9 in the control box 20, which connection rotates the arrow Ill and lead screw 56 to an angular extent equal and opposite to the angular rotation of the gun in azimuth so that the orientation of the arrow and lead screw relative to the earth is preserved as the gun rotates, and the lead screw remains in its pre-set relation, parallel to the target course. This connection includes a bevel gear 59g (Fig. 1) which is rotated by azimuth crank 59, and drives bevel pinion 6I on a shaft 6I which may be conventionally connected to traverse gearing below, not shown. The shaft includes a coupling part, not shown, mounted for rotation in a gear box 60 and adapted to be coupled by a socket member II'I, with a shaft IIE journaled in the box. A friction disc 6'2 is splined on shaft II6 and is pressed axially upwardly as seen upon Figure 11, by a spring I I9 reacting against a collar I`I8 pinned on the shaft, as subsequently described. An upper disc 63 is in frictional engagement with disc 62. Disc 63 is operatively connected to one end of the core of a flexible shaft .64, a friction face material being interposed (Fig. 11) The other end of flexible shaft 64 is operatively connected at a second gear box 65 mounted rigidly on shaft 23 (Figs. l and 2), to a shaft 65 which leads into control box 20 where it is provided with a worm 66u; which meshes with a worm gear 61, (see Fig. '7) which is rotatively mounted on the tubular hub or shaft I'Ih o-f the swingable bracket member Il, in which the lead screw 55 is mounted, as already described. The worm gear 61 is in frictional driving engagement, through friction elements, such as cork inserts 68, with the side of the aforedescribed spur gear I6 which is secured, as already explained, to the swingable bracket member I'I.

Hence rotation of azimuth crank 59 will rotate member Il through the friction discs 62-63, the flexible shaft 64, and the friction member 68. The purpose of the friction member 66, Fig. 7, is to permit the hand setting of arrow I0, by means of the gears I2-I3 and I5-I6, Fig. 8. In setting the arrow and lead screw by hand in this manner, the spur gear I6, Fig. 7, slips at the friction member 68 relatively to the worm gear 6l and thus is not blocked by the worm connection 61-66w and the drive connection to gear box 60. The friction discs 672-63, Fig. l1, are provided to enable the arrow and lead screw to be adjusted by hand at the gear box 6U alternatively or additionally to setting of the arrow by direct manipulation of the latter. The gear box 60, located near the azimuth trackers crank 59,

is nearer the breech end of the gun than is the control box 26 and its arrow l0, and consequently it would be more convenient for a sight setter who stands behind the azimuth tracker to make the pre-setting of the arrow and lead screw from the gear box 60 than from the control box 20. Mounted to rotate with the upper friction gea* disc 63 is a double gear 63g, Fig. 1, which is driven by large gear 69g mounted in the gear box 60 to rotate with a hand wheel 69, its bevelled upper part driving a bevel pinion on the flexible shaft 64, as at l0, Fig. 11. Hence by turning hand wheel 69 rotation may be imparted by flexible shaft 64 to the arrow and lead screw in the control box 20 (through the connections already described). The friction disc 63 slips on its companion spring loaded friction disc 62, and thus is not blocked by the bevel gears 6I-59g and the azimuth crank 59.

The axially positionable nut 55 of lead screw 56 is articulated to the rod 56' by a universal joint 49, see Fig. '7. Lead nut 55 is provided with a pin 55p which is slidably received in a long 'slot Ils in the swingable bracket member I'I and parallel to lead screw 56. Pin 55p and slot Ils are provided to prevent rotation of nut 55 so that it must move axially along the lead screw 56 as the latter is turned. Lead screw 56 is pivotally supported at its ends in bearings provided in the aforedescribed swingable bracket member Il, and is provided with a bevel gear 56h fixed on its inner end and which meshes with a bevel gear 41h which is secured at the lower end of a vertical shaft 4l rotatively mounted in control box 29 on the axis of rotation of the bracket Il.

Near its upper end a p-inion 47g is also secured to shaft 4l, said gear 47g meshes with one or more planetary pinion double gears Sip which are rotatively mounted on the upper face of a carrier sun gear 3l which is itself rotatively mounted on the vertical shaft l'l. The said planetary pinions 31p are each integral double gears, one end of each gear 37p meshes with pinion 41g on shaft 4l, as already described; the other ends engaging with a spur gear 36p which is rotatively mounted on the vertical shaft 4l. Secured to spur pinion 36p to rotate therewith is a bevel gear 36h which meshes with a bevel gear 35h secured at the right end of a short horizontal shaft 35, as viewed in Fig. '7, and near the left end of this shaft is secured spur pinion 35p which meshes with a large gear 36g secured near the right end of a horizontal spindle 30s mounted through the case 26, its left end being outside the control box 20, for securement thereon of the aforedescribed spoked handwheel 39. See the planetary system I9 in Fig. 12.

The said sun gear 3l, meshes with a pinion I8, Fig. 8, `which is secured on the vertical shaft I4.

As explained above, spoked handwheel 30 is turned to enter a vector value for the speed of the plane target into the control box and causing axial adjusting of the position of the nut 55 a distance along the lead screw from its zero position at the vertical axis of shaft 4l. Handwheel spindle 36s is provided with a pinion 36p which meshes with a gear 32g which is rotatively mounted together with an indicator disc 32 secured thereto, on the aforementioned shaft 35. Disc 32 is provided with a speed scale which is readable in indicator window 22 of the control box. Turning of handwheel 36 is communicated, through the train of gears described above, to the pinion gear 36p, to rotate this pinion about the vertical shaft 4l, The differential 31--3'Ip saai-l recu is provided so that errors in speed setting of nut 55 which otherwise would be caused by rotation of screw 56 and member I1 while shaft 41 is stationary, are eliminated. Such take out differentials are well known in the art so that further description is deemed unnecessary. Continuing with the description of the target speed instrumentalities 30--31-56, it will be assumed that the arrow aligning instrumentalities are not being motivated at the time speed handwheel 30 is manipulated. That is, the pinion I8 on shaft I4 is held stationary. Planetary carrier gear 31 being in mesh with pinion |8, will likewise be stationary. Inasmuch as the planetary carrier gear 31 is held against rotation, the turning of pinion 36p will be communicated, through the planetary pinions 31p, to gear 41g and vertical shaft 41 and through bevels 41h-56h to lead screw 56. By reason of the bevel gear connection 41h-56h between vertical shaft 41 and lead screw 56, rotation may be imparted to lead screw 56 irrespective of the angular orientation of the lead screw by its carrier I1.

It should be understood that the organization of the directional connections between the arrow and bracket I1 and the setting means at 69 on the one hand, with the speed input setting means 30-I4-56 on the other hand, through the medium of the differential sun and planet gears with the sun gear 31 directly connected at I8 with the shaft I4, has an important and novel effect in the invention in preserving any given speed setting of dial 32 despite variations of position of the lead screw. In swinging the screw 56 there is a tendency, unless counteracted, for the gear 56h to travel on the gear 4112, rotating the screw in the nut 55 and so changing the vector value of the position of the nut without the change appearing at the dial 32; or, if the gear 5612 does not travel on gear 41b, but remains nonrotatively in position on the latter, and causing it to turn, the motion that would thus result (through shaft 41, gears 41D, etc., to dial 32) would produce a change of the indication of speed set in, contrary to the actual position of the nut element 55.

It has been described above, with reference to Fig. 1, that shaft 58 serves to transfer the lateral lead turning of the azimuth trackers telescope 50 (on the right or azimuth trackers side of the gun) to the elevation trackers telescope 90 (on the left or elevation trackers side of the gun) and that shaft 48 serves to transfer the superelevation turning of the azimuth trackers telescope 50 to the elevation trackers telescope 90.

It has been described above that the telescopes, e. g., the azimuth trackers telescope 50, is initially adjusted, by means of clamping arm 5|a and the nut and slot arrangement shown in Fig. 3, to be parallel to the gun bore, by sighting at a xed target in a procedure known as bore sighting. As explained above, the Weiss sight is designed with a pre-determined angle of super- `elevation for zero permanently set in for an average range of encounter for the type of gun indicated. This included superelevation must be eliminated during bore sighting. For this reason the link 25, which connects the distal end of lever 24 to fixed point 4a of the gun mount for the purpose of maintaining control box 20 vertical and arrow I0 horizontal, is articulated to the distal end of lever 24 in a manner to facilitate the disconnecting of the link 24 from its lever 25. In bore sighting link 25 is disconnected from lever 24 (as shown by the dot-and-dash position of the link in Fig. 9a). The parts are shown in Figs. 9a and 10a when bore sighting with the gun horizontal. Hence the strap 43 and the slot 6 (in frame member 3, see Fig. 5) in which eccentric pin 26 of shaft 23 is received, are horizontal, see especially Fig. 10a. As explained previously, in conjunction with Fig. 5, strap 43 is in its most depressed position when the gun is horizontal so as to introduce the maximum amount of superelevation.

After disconnecting link 25 from lever 24, lever 24 is turned clockwise 90 to the dot-and-dash position shown in Fig. 9a. It should be apparent that this clockwise turning of lever 24 by hand is precisely equivalent to the 90 turning it would be received were the gun itself elevated 90. It lshould be recalled that the parts are designed so that superelevation is entirely eliminated when the gun is pointed vertically. That is, the said 90 clockwise turning of lever 24 and shaft 23 to which it is secured causes a raising of the strap 43 to its uppermost position in which all superelevation is eliminated and the telescope 50 brought parallel with the axis of bore of the gun, Fig. 9a.

To provide a gauge for determining the ysaid 90 turning of lever 24 and shaft 23 a short arm 21 is extended from arm 24, Figs. 5, 9 and 9a, and provided at its distal end with an aperture 21a. The strap 43 is provided with a hole 43h which is so located relatively to short arm 21 and its aperture 21a that when lever 24 is turned 90, as shown in dot-and-dash, Fig. 9a, aperture 21a will register with hole 43h. The parts may be maintained in this position by passing a pin or other tool through 21a and 43h.

It may be noted that the case 20 has a removable side cover plate |00 which extends over the right side and part of the front of the case, its removal exposing the gearing for servicing or repair.

In order to obviate loose movement of the lead screw 56 and its floating bracket I1 and to close the case against access of dust there is secured between the bracket and gear I6 a resilient annular plate I 0| with an annular concentric channel therein having a soft cushion material |02 bearing against the under side of a circular hood |03, which is attached to and closes the lower open side of the case 20, as Well as projecting outward thereof so as to cover the entire path of horizontal rotation of the bracket I1, thus preventing interference with orienting rotation of the lead screw as well as protecting it from damage.

The bracket I1 and attached gear I6 are supported upc-n a spring |04 which is confined between a split collar |05 on the upper end of the hub |1h of the bracket I1, and a bushed split bearing arm |06 formed on the body of the case 20. The hub is externally threaded, and the collar is interiorly threaded, split, and screwed upon the hub to hold the parts in proper assembled relation, the collar being clamped on the hub by a screw |01 engaged across the split. The collar is recessed on its underside to receive a thrust ball bearing unit |08, against which the spring is seated, and a similar antifriction unit is inserted between the arm |06 and the upper side of the worm gear 61. A clamp screw |09 closes the opening in the arm |06 tightly around the bushing III) therein.

To minimize access of dust to the lead screw and its operating gearing, and to also keep the path of the bracket l1 Within the hood |03 clear,

a circular plate HI' (Fig, 7) is mounted on the under side of the bracket, having an upturned portion H2 extended over the outer end of the bracket and being supported opposite the lead screw by an attached support arm or bracket I I3 attached in any convenient manner to the bracket I'|. The slot Ils before referred to may be formed in this plate and the nut 55 may in addition be provided with horizontal lateral flanges H4 which lie close under respective depending guide walls l I5 of the bracket extending along each side parallel to the screw to the outer bearing for the screw 55.

The azimuth gearing is only shown formally without reference to actual construction, and for the m'm. gun the standard gearing is used. Our gear case is constructed in practice so that it may be secured on top of the upper case of the standard azimuth drive, in place of the usual square cap heretofore used to close the top end of the case.

For effecting a coupling with the standard gear, a vertical shaft H6 (Figure 11) is revolubly mounted in the gear box 60 having on its lower end a short sleeve or socket member adapted to fit on the usual nut pinned at the top of the azimuth drive heretofore, or any fitting which may be found preferable. The shaft H6 has a coupling collar H8 pinned thereon within the box 60, and the disc 62 is slidable on this shaft keyed with the collar H8 and loaded by a helical spring H9 confined between the collar and disc. The top disc 63 is helduby a thrust collar |20 pinned to the shaft i I6 thereover, and is suitably recessed to hold the friction facing material |2I. i

The disc is formed with a rosette clutch portion |22 extended revolubly around the collar |20, and engaged with a corresponding opposed part |23 of a socket hub |24 of a bevel gear |25 set revolubly and removably on an extended upper end of the shaft I6. The gear |25 is mounted in a cap case part |26 secured on top of the box 60 and is meshed with the bevelled pinion '|0 also mounted in the cap case and connected to the flexible shaft 64. The disc 63 may be spurtoothed on'its periphery and with the gear part |25 may constitute the double gear 63g shown in the schematic view. A small double gear |28 is mounted in the case 60 as a motion multiplying gear meshed between the large gear 69g and the lower part of the double gear 63g.

The latter arrangement enables the forward location of the large gear 69g and hand wheel so as to avoid interference with the standard azimuth hand cranks.

In Figure 13 the parts shown are all described in the foregoing description and have the same reference numerals applied. But some detail features described and shown in other views are omitted and alternate structure of a simpler nature shown. Thus, while the complete system of gearing at the control box is shown as described, and may be referred to for a ready grasp of the functions of the mechanism, the friction facings and specific structural mounting are omitted. The mountings of the telescopes are conventionalized and reference may be made to the other views for these features as specifically described. In this gure it is shown how the hand wheel 69 may be set directly over the standard azimuth gearing shaft 6| and to rotate directly therewith with the described friction coupling interposed.

Figure 12 represents the differential gearing as the sight.

used in Figures 7 and 8, segregated and simplified for ready perception of its function.

For a more detailed description of the geometrical and ballistic principles in the construction and function of this invention, reference is made to the said prior application of Herbert K. Weiss.

While this invention hashad for its object the evolution of improved operative means broadly included in the aforesaid prior application of Weiss, certain new features of invention have been evolved as hereinafter claimed; but it will be understood that as to the novel features this disclosure is exemplary, and that the invention is entitled to an appropriate range of equivalents: changes in form and arrangement, substitution of materials and equivalents, structural and otherwise, being in the spirit of the invention.

It should be understood that in the construction shown, the functioning of the lead screw in rotative adjustment on its vertical axis and the setting in of the speed of the target, serve to convert horizontal lead into a factor of elevation proportionate to that required to compensate for movement of the target toward or away from the gun (on incoming or outgoing legs of its course). Thus, assuming a direct approach or departure on a horizontal course at an average height, the adjustment of the rider that would on a crossing target introduce lead only is completely neutralized as to lateral lead by the swinging of the lead screw into parallelism with the target path and vertical plane of the gun, and the lead is manifest as elevation only. That is to say, the gun being elevated, the shaft 45 is brought below the shaft 23, and the lead screw being swung in a horizontal plane around the axis of shaft 41, moves above or below a line between the shafts 45 and 23, swinging the linkage Eid-54 similarly, according to its direction, as indicated by the arrow. On the incoming leg, the screw extends forwardly from the shaft 41, and below the line between the shafts 45 and 23, and so depresses the sight, importing positive elevation value into the relation of the gun to On the other hand, if the target is departing on the same path and is in the same position, the screw 21 is reversed in direction and the linkage is swung over the line between the two shafts, so that the telescope is elevated correspondingly. The telescope being trained on the target, the gun will be depressed below the line of sight for the departing target. It will be apparent, too, that the degree of depression of the gun below the line of sight on a departing target at a given position is greater than the degree of elevation above the line of sight on an approaching target at the same position, so that the greater deceleration of the projectile in the outgoing leg of the course as compared to the incoming leg, will be compensated for. This factor of elevation component in lead varies directly Iwith the degree of elevation, and inversely with the angle of approach.

We claim:

1. In a gun having traversing and elevating mechanism including an azimuth trackers telescope and an elevation trackers telescope, in combination, a vertical spindle, an arrow horizontally secured at the top of the said spindle, a lead screw operatively connected to the said arrow spindle to turn in synchronism therewith, whereby manual adjustment of the said arrow into parallelism with the path of a target will orient the said lead screw parallel to the target path, a rider on the said lead screw adapted to be axially adjusted thereon by screw rotation, means operatively connecting the said rider with the said azimuth trackers telescope to turn the same in accordance with said axial adjustment of the rider, manual means for rotating the lead screw to adjust its said rider in accordance with the estimated speed of the target, whereby the said telescope is turned in azimuth relatively to the gun to introduce lateral lead, means for vertically adjusting the said lead screw and its rider in accordance with gun elevation to introduce superelevation, and parallelogram linkage mechanism connecting said telescopes for pivotal movement in unison to maintain their lines of sight parallel.

2. In a gun having traversing and elevating mechanism including an azimuth trackers telescope and an elevation trackers telescope, in combination, a vertical spindle, an arrow horizontally secured at the top of the said spindle, a lead screw operatively connected to the said arrow spindle to turn in synchronism therewith, whereby manual adjustment of the said arrow into parallelism with the path of a target will orient the said lead screw parallel to the target path, a rider on the said lead screw adapted to be axially adjusted thereon by screw rotation, a telescopic rod articulated to the said rider and provided with a bracket at its other end, manual means for rotating the lead screw to adjust its rider in accordance with the estimated speed of the target, means on the said bracket mounting the azimuth trackers telescope whereby the said telescope is turned in azimuth in response to the said lead screw o-rientation in parallelism to the target path and to the axial adjustment of the rider in accordance with target speed, means for vertically adjusting the said lead screw and its rider in accordance with gun elevation to introduce the required superelevation, and a shaft articulated at one end to the said bracket by a vertical pin passing through the said telescopic rod whereby the said rod may turn in azimuth about the said vertical spindle and whereby the azimuth trackers telescope is turned in elevation about the said shaft.

3. The combination according to claim 2 further provided with means connected to the said bracket for turning the said elevation trackers telescope in synchronism Iwith the said azimuth turning of the telescopic rod and means connected to the said shaft for turning the said ele-- vation trackers telescope in synchronism with the said elevation turning of the said rod.

4. The combination according to claim 2 further provided with a bracket provided with means mounting the elevation trackers telescope thereon, a shaft articulated to the said bracket by a vertical pin, linkage means between the said bracket associated with the azimuth trackers telescope and the said bracket associated with the elevation trackers telescope to turn theelevation trackers telescope in synchronism with the said azimuth turning of the azimuth trackers telescope, and linkage means between the said shaft associated with the azimuth trackers telescope and the said shaft associated with the elevation trackers telescope to turn the elevation trackers telescope in synchronism with the said elevation turning of the azimuth trackers telescope.

5. The combination according to claim 2 further provided with linkage means including a pair of shafts for turning the said elevation trackers telescope in synchronism with the said azimuth and elevation turning of the azimuth trackers telescope, and a tubular frame member carried by the gun and adapted for supporting-` the foregoing parts, the said pair of shafts extending through the said tubular frame member fromthe azimuth trackers to the elevation trackcrs side of the gun.

6. In a computing sight, in combination, an arrow adapted to be manually adjusted into parallelism with the path of a target, a vertical shaft, a carrier rotatively mounted on the said vertical shaft, a horizontal lead screw rotatively mounted in the said carrier, a rider on the said lead screw adapted to be axially adjusted thereon by screw rotation, a spur gear rotatively mounted on the said vertical shaft and secured to the said carrler to rotate therewith, operative connection between the said arrow and the said carrier gear, manual means for rotating the said vertical shaft in accordance with the estimated speed of the target, and a bevel gear connection between the I lower end of the said Verticalshaft and the said lead screw, whereby the said carrier and its lead screw may be turned synchronously with the said manual adjustment of the said arrow and independently of the axial adjustment of the said rider along its lead screw by the said rotation of the vertical shaft in accordance with target speed.

7. A sight as set forth in claim 6 including an operative connection between said vertical shaft and said carrier to rotate said shaft when the carrier is moved azimuthally, whereby the position of said means to rotate the vertical shaft and the position of the rider on the lead screw are maintained in agreement.

8. In a computing sight, in combination, an arrow adapted to be manually adjusted into parallelism with the path of a target, a vertical shaft, a, carrier rotatively mounted on the said vertical shaft, a horizontal lead screw rotatively mounted in the said carrier, a rider on the said lead screw adapted to be axially adjusted thereon by screw rotation, operative connection between the said arrow and the said carrier, means for rotating the said vertical shaft in accordance with the estimated speed of the target, and a bevel gear connection between the lower end of the said vertical shaft and the said lead screw, whereby the said carrier and its lead screw may be turned synchronously with the said manual adjustment of the said arrow and independently of the axial adjustment of the said rider along its lead screw by the said rotation of the vertical shaft in accordance with target speed.

9. In a gun and sight of the character described, a traversable carriage, an elevatable gun member thereon, a sight mounted on the elevatable member ypivoted for super-elevational adjustment, a fcrwardly extending member connected to the sight movable vertically to move the sight on said pivot, a compensator revoluble on said forwardly extending member and having an eccentric part connected with the gun member in an initial relation to support saidvforwardly extending member at a lowered position, an arm extended from said eccentric, and a link therefrom to the carriage in a relation to rotate the eccentric on rising movements of the gun to lower the eccentric, for the purpose described.

10. In an automatic lead imposing sight, a lower sight support, a revoluble member thereon, rotatable on a vertical axis, a post coaxially revoluble thereon, means to releasably secure the post thereon, an upper member having a transverse u upper member has a dependent plate beside the post, a slot in one and a headed screw in the other engaged through the slot to clamp the two together at adjusted positions.

12. In a lead-computing gun sight, a case, a shaft journaled in said case for rotation upon a rst axis, a bracket journaled in said case for rotation on said rst axis, a lead screw journaled in said bracket for rotation about a second axis normal to and intersecting said rlrst axis, gearing interconnecting said shaft and screw for rotation in unison, a nut threaded on said screw and translatable therealong in response to rotation of said screw, first means including a differential to rotate said shaft and thereby said screw, second means operable to rotate said bracket and screw to vary the direction of said Screw, a driving connection between said second means and said differential, a sight, and a connection between said nut and sight. Y

13. A lead computing gun sight comprising a case, a normally vertical shaft journaled in said case for rotation upon a first axis, a bracket journaled in said case on said axis, a lead screw journaled in said bracket on a second axis normal to and intersecting said rst axis, gearing interconnecting said shaft and screw for proportional rotation, a nut threaded on said screw and translatable only therealong in response to rotation of said screw, a differential having its center connected to said shaft, arrow means journaled on said casing on an axis parallel to said shaft, a driving connection between said arrow means and a iirst side of said differential to vary the direction of said Screw, a target speed set, driving connections from said set, the second side of said differential, a sight pivoted on a third axis offset from and parallel with said first axis, and a telescoping rod connection between said nut and said sight.

14. A lead-computing gun sight comprising a case, a shaft and a bracket journaled in said case for independent rotation about a common normally vertical rst axis, a lead screw journaled in said bracket for rotation upon a second axis normal to said first axis, a lead nut engaging said f screw and translatable along said second axis in response to rotation of said screw, means connecting said shaft and screw for conjoint rotation, a stud journaled in said casing on a third axis parallel to said rst axis, a directional arrow adjustably fixed to said stud normal to said third axis, a differential having its center xed to said shaft, a driving connection between said stud and one side of said differential whereby to connect said arrow and screw for synchronous rotation about said third and rst axis, respectively, and in the same direction, a manually operable speed set carried by said case, a driving connection between said speed set and the remaining side of said differential, a post laterally spaced from and substantially parallel to said shaft, a sight carried by said post with its line of sight substantially normal thereto, and a telescoping link connection between said nut and post, whereby rotation of said bracket and screw about said rst axis and translation of said nut along said second axis, effects pivotal adjustment of said post and sight.

15. A gun sight as recited in claim 14, and means adapted to mount said gun sight upon a CII gun and operable to maintain the axes of said shaft and post substantially vertical for all angles of gun elevation.

16. A gun sight as recited in claim 14, and means adapted to mount said gun sight upon a gun, said means including a second shaft journaled eccentrically on said gun upon an axis parallel to the trunnion axis of the gun, a second bracket fixed to said shaft and carrying said case, and means responsive to change in gun elevation to maintain said shaft rotationally fixed to thereby move said second bracket, case and parts carried thereby vertically, relatively to the gun, in proportion to the angle of gun elevation.

17. A superelevation corrector for a gun, a post, a sight carried by said post with its line of sight normal to said post, rst means mounting said post on said gun for pivotal movement about the axis of said post and a second axis parallel to the axis of elevation of said gun, a bracket spaced forwardly of the post in the direction of the bore axis of said gun, lead computing mechanism carried by said bracket, a connection between said post and mechanism operable to shift the line of sight of said sight angularly with respect to the gun, in accordance with lead, and means mounting said bracket and post on said gun, said lastnamed means being operable to maintain said post and mechanism in predetermined relation to the vertical in a plane parallel to the vertical plane through the bore axis of said gun, and including means to shift said mechanism transversely of the gun in said plane in accordance with the cosine of the angle of gun elevation.

18. In a gun sight for a gun elevatable on a trainable carriage, rst and second aligned shafts journaled on a normally horizontal first axis on respectively opposite sides of said gun, an arm projecting radially from each shaft, a third shaft i journaled upon a second axis spaced along the bore axis of said gun from said first axis and having an arm xed at each end transversely thereof, links connecting the arm of each of said pair of shafts in parallelism with a respective arm of said third shaft, a box pivoted on each of said first and second shafts upon third and fourth axes each normal to said first axis, a spindle xed to each box parallel to said third and fourth axes, a rod secured to each box transversely of said third and fourth axes, a fourth shaft journaled adjacent and parallel to said third shaft and having an arm xed at each end transversely thereof, pivoted link means connecting each arm of said fourth shaft with a respective one of said rods, a sight mounted on each said spindle, said sights having their lines of sight parallel, and a lead computing mechanism connected to one said box, said linkages being operable to retain said sights in parallelism for all angular positions thereof relatively to said gun.

19. In a gun having traversing and elevating mechanism including an azimuth trackers telescope and an elevation trackers telescope, in combination, a vertical shaft, an arrow horizontally secured at the top of said shaft, a lead screw operatively connected to said shaft to turn in synchronism therewith, whereby manual adjustment of said arrow into parallelism with the path of a target will orient said lead screw parallel to the target path, a rider on said lead Screw adapted to be axially adjusted therealong by screw rotation, connecting means between said rider and said azimuth trackers telescope to Sittltltih @00M turn the telescope relatively to said gun in accordance with turning and rotation of said Screw, manual means for rotating said lead screw to adjust said rider in accordance with the estimated speed of the target, whereby said telescope is turned in azimuth to introduce lateral lead, a bracket member associated with said connecting means, a po-st projecting upwardly from said bracket member and provided with a pair of forked fingers at its upper end, a clamping member secured to said azimuth trackers telescope and provided with a depending portion received between said forked fingers, a spindle fixed to said clamping member for pivotally mounting said clamping member in said forked lingers, a plate secured to said spindle and provided with an arcuate slot, and a bolt passing through said slot to adjustably secure said plate to said post thereby to hold the telescope in adjusted angular elevational relation to said connecting means.

20. In a gun having traversing and elevating mechanism including an azimuth trackers telescope and an elevation trackers telescope, in combination, a vertical shaft, an arrow horizontally secured at the top of said shaft, a lead screw operatively connected to said shaft to turn in synchronism therewith, whereby manual adjustment of said arrow into parallelism with the path of a target will orient said lead screw parallel to the target path, a rider on said lead screw adapted to be axially adjusted therealong by screw rotation, connecting means between said rider and said azimuth trackers telescope to turn the telescope relatively to said gun in accordance with turning and rotation of said screw, manual means for rotating said lead screw to adjust said rider in accordance with the estimated speed of the target, whereby said telescope is turned in azimuth to introduce lateral lead, said gun having an elevatable part and a non-elevating traversable mounting therefor, a casing for said arrow shaft and lead screw, a lateral horizontal rotatable shaft, a pair of arms pivotally mounted on said elevatable part and provided at their distal ends with bearings for said lateral shaft, said casing being fixed on said lateral shaft, linkage means between said non-elevating gun mounting and said lateral shaft adapted upon gun elevation to turn said lateral shaft in the opposite sense whereby said arrow shaft is maintained vertical for all positions of gun elevation, said gun part being provided with an elongated longitudinal slot adjacent said lateral shaft, an eccentric pin on the end 0f said lateral shaft and received in said slot, whereby turning of said lat- 18 eral shaft in response to change in gun elevation will relatively rotate said lateral shaft on said pin to thereby angularly adjust said telescope for superelevation in accordance with the angle of gun elevation.

21. An on-carriage sight mount for a gun mounted in a cradle pivoted for elevation about a normally horizontal trunnion axis on a trainable base, a tube xed to said cradle parallel with the trllnnion axis and projecting to each side thereof, rst and second frame members xed to the respective ends of said tube, an azimuth telescope, an elevation telescope, means mounting each telescope on a respective frame member for pivotal movement about normally horizontal and vertical axes, a pair of parallel shafts mounted for rotation in and extending through said tube in parallel relation therewith, a lever Xed to each end of each shaft, first parallelogram link means connecting each lever of one shaft with a respective sight to connect said sights for movement in unison about their horizontal axes, and second parallelogram link means connecting each lever of the other shaft with a respective sight to connect said sights for movement in unison about their vertical axes.

WILLIAM F. BERNART, JR. FRANCIS J. ROUAN. FREDERICK L. FORD. RAYMOND L. THATCHER., Administrator of Estate of Linden A. Thatcher,

Deceased.

REFERENCES CITED The following references are of record in the 111e of this patent:

UNITED STATES PATENTS Number Name Date 1,650,628 Inglis Nov. 29, 1927 1,651,093 Le Prieur NOV. 29, 1927 1,915,191 Le Prieur et al. June 20, 1933 1,962,590 I-Iaub-roe June 12, 1934 2,237,613 Petschenig Apr. 8, 1941 2,372,613 Svoboda Mar. 27, 1945 FOREIGN PATENTS Number Country Date 494,895 Great Britain Oct. 31, 19318 536,682 Great Britain May 23, 1941 693,295 France Aug. 19, 1930 OTHER REFERENCES Gesellschaft Fur Nautische Instru., 7,497, 1913. La, Precision Moderne840,363, Jan, 16, 1939. 

